Locomotive



April 23, 1929. E. L. SCHELLENS ET 1. 1,710,244

LOCOMOTIVE Filed July 25, 1925 INK? zi w BY WgSRNEYS NZOE Patented Apr. 23, 1929.

UNITED STATES PATENT, OFFICE. I

EUGENE L. SCHELLENS, OF POINTE CLAIRE, QUEBEC, CANADA, AND JOEL S. COFFIN,

JR., OF LISBON, NEVV' HA'MPSHIRE, ASSIGNORS, BY DE nor AND MESHE Assre-N- LOCOMOTIVE.

Application filed July, 23, 1925. Serial No. 45,495.

This invention relates to locomotives and its nature, objects and advantages will be best understood from the following:

Locomotive development and design is subjected to very definite limitations, one of which is the matter of clearance. The most important factor of limitation, however, is the matter of weight which is fixed by bridge constructirm, primarily. To meet the growing demands on motive power, it has been the practice to lengthen the train, i. c., increase the tonnage hauled. To start the heavier trains, locomotives have recently been equipped with booster devices, driving normally idle wheels, such boosters being used in starting and in maintaining the trains in motion at slo. speed. The use of boosters,

, upon the boiler horse-power developed at any I however, has the limitation that there is a tendency to drain the boiler of steam, particularly onlong, heavy grades. This condition cannot be well met by increasing the size of the boiler, because of the weight limitations hereinbefore mentioned. Present methods of drafting the locomotive also impose limitations, particularly at the slow speeds when, of course, particularly Where a booster is used, the steaming capacity should be adequate for both the main engines and the booster engines.

It is one of the primary objects of our invention to overcome the foregoing difficulties.

More especially, it is an object of our invention to provide a locomotive which, although within size and weight limitations, nevertheless will start heavy tonnage and maintain it in motion for long periods over long grades without overtaxing the boiler capacity.

It is also an object of our invention to clnnge the characteristics of the boiler with regard to speed over the present standard practice. In this connection the tractive horse-power of a locomotive is dependent speed. The boiler horse-power developed varies with the speed, increasing as the speed goes up. This introduces difliculties such as will readily be appreciated from the following. If, for example, a locomotive is equipped with three cylinders to secure more uniform starting torque, it could utilize more boiler horsepower at low speeds than a standard locomotive, but such increased horse-power is not available, due to the aforementioned limitations to size and Weight. This is also the case with other multiple cylinder locomotives such as thedalletor other compound; andsimilarly with overcylindered locomotives operating on limited cut off.

More specifically, in this regard, therefore, we propose a locomotive capable of developing maximum boiler horse-power and hence maximum tractive horse-power at low speeds. We also a-imuto secure higher boiler horsepower 'at low speeds than can normally be obtained at speed in a standard locomotive of the same class.

.The attainment of the foregoing enables us to greatly increase acceleration and to shorten the time required to get over divisions, particularlyfiin hi ly districts.

The preferred manner in which weaccomplish the forogoin g and such other objects and advantages as may hereinafter appear, is illustrated in the accompanying drawing, which is a diagrammatic side elevation of a locomotive constructed and operated in accordance with our invention.

In practicing our invention as applied to a standard type of locomotive, we prefer to equip normally idle weight carrying wheels such as the wheels 7 of a trailer truck with a booster motor 8. These wheels 7 are usually of smaller diameter than the main drivers 9 and, therefore, have a higher factor of adhesion. The booster motor, therefore, greatly increases the tractive effort exerted by the locomotive, considered as whole, and, thercfore, the locomotive is able to start a. heavier train and will maintain such a heavier train in motion at slow speed.

To overcome the difficulty incident to the tendency to drain the boiler on long grades at slow speed when both the main engines and the be saerarc in operation, we substitute for the usual draft nozzle, a draft appliance, such as shown in our copending application Serial No. (381,450, filed Dec. 18. 1923. The draft appliance includes, inter alia, draft creating fan operated by exhaust steam from the main engine, as by a turbine, (not 7 fully shown), the buckets of which are indicated at 11. lVe have discovered that such a draft fan, contrary to expectations, produces more steam at slow speed. We are not certain as to the precise cause for this, but actual experience has demonstrated that the heavy, intermittent pulsations of exhaust steampsuch as would'occur, for example, in pulling a train over a 1on 'rade, cause our new fan to create more draft than when running at rates even higher than the very high rate at which present locomotives are fired. In other words, we are able to develop more steam with a standard boiler of a standard locomotive, at low speed, than heretofore possible. Thus by availing ourselves of this unexpected characteristic of our draft appliance and by employing such a fan in the combination of parts described, we provide a locomotive which can start heavy tonnage and maintain the same 1 w speeds on heavy pulls witlr out overtaxing the boiler. Furthermore, we

are enabled to operate such a draft appliance with a lower back pressure than is possible with the standard nozzle and we thus increase the tractive effort exerted by the locomotive itself, irrespective of the increase in tractive effort developed by the use of the booster or other means. Thus a standard lo--- comotive, equipped in accordance with our invention, Wlll take a heavier train over the division at higher speed than would otherwise be possible.

In the construction of new engines, we prefer to employ the same organization'of parts, but. in addition, we lower the factor of adhesion of the main drivers below that which would be normal for the particular class of locomotive. We prefer to accomplish this by stepping up the boiler pressure or otherwise overcylindering the locomotive. Such a locomotive we operate at a limited cut-oil so as toestablish a practicable relation betweenadhesive weight and draw-bar pull in star ing. Stated in other words, by operating such a locomotive with limited cuc-olf, for example, 50 to 60%, it exerts about the same starting effort as would locomotive of standard construction of the same class. The booster would increase this starting effort so that a heavy train could be started and moved at slow speed. The effect of the limited cut-oh is that the locomotive itself exerts still greater tractive effort at speed. Since an increase Y tor of adhesion.

in boiler pressure might involve increased weight, the peculiar characteristic of the exhaust-steam operated turbine fan draft appliance above noted will make it possible to develop the necessary quantity of steam with a smaller boiler, or without increasing the size of the boiler. Thus weight limitations can be observed. I

Turning now to the other types of locomotives horeinbefore referred to, namely, such ty es as could inherently utilize more boiler horse-power at low speeds than is developed by the boiler, it will be seen that by employing a draft device of the characteristics referred to, we are able to develop maximum boiler horse-power at low speeds and to start, accelerate, and move the trains more readily and rapidly than heretofore. In this connection, whereas in a standard locomotive, the boiler horse-power curve rises in a straight line and reaches its pealr approximately forty miles per hour, in our arrangement the boiler horsepower curve rises in a straight line almost vertically, reaching its peak at very low speed.

Furthermore, we find that we obtain amuch higher degree of super-heat at low speeds and we thus obtain the advantages of high degree superheated steam over a much wider range of speed than heretofore.

The development of high super-heat at starting has verymaterial etfect on the tractive forcecurvebecause there is little or no condensation in the cylinders such as occurs in standard locomotives.

We claim:

1. The combination of a steam locomotive inherently capable of utilizing more boiler horsepower low speeds than developed by the boiler with standard drafting, and an exhaust steam operated turbine draft creat ing fan. 2. In combination, a locomotive and its main engines and drivers, abooster notor adapted to crive normally idle wheels in starting and at slow speeds, and an exhauststeam-actuated turbo fan for drafting the locomotive.

8. In combination, a locomotive and its main engines and drivers, boostermotor adapted to drive normally idle wheels in starting and at slow speeds, and an exhauststeam-actuated turbo fan for drafting the locomotive, the locomotive having alow facat. In combination, a locomotive and its main engines and drivers, abooster motor .oapted to drive normally idle wheels in P. starting and at slow speeds, and an exhauststeam-actua'ted turbo fan for drafting the locomotive, the locomotive having a low factor of adhesion and beinqoperated on limited maximum cut-0E.

5. In combination a locomotive having a boiler smaller than provided for a standard locomotive of the same class to do the same amount of Work, and am eXhaust-steamin proportion to the frequency of exhaust actuated turbo fan for creating the draft of steam impulses, at low speeds of the locomo- 10' the locomotive. tive than at high speeds.

6. In combination, a locomotive having In testimony whereof, we have hereunto 5 cylinder capacity in excess of the normal Signed our names.

boiler capacity of a locomotive of that pai i ticulzir class, and an exhaust-steztm-opera-ted EUGENE L. SCHELLENS. draft fan adapted to create a draft greater, J. S. COF FIN JR. 

